Time-resolved studies of parametric instabilities in laser-produced plasmas of near-critical density

In the context of research on laser interaction with ultra low-density porous media, comparative experiments with thin, burning through plastic foils have been carried out. The structure of backscattered spectra near the laser fundamental frequency was observed and analyzed taking into account the simultaneously temporally and spectrally resolved measurements of the second harmonic emissions. Parametric instabilities responsible for the emissions are identified.